Thursday, July 11, 2013

Is Chris Froome Doping? A look at the pseudo-evidence

Outside Magazine--the rag that Lance built--recently posted a downright libelous piece on Froome. The article draws on the assertions of Antoine
Vayer and Science
of Sport and Cyclismas in suggesting, merely by how fast he's going, that Froome is doping. Froome's extraordinary performanceExtraordinary fast
The specific instance of their analysis is his attack on Ax-3 Domaines, where he gained minutes on the field. Ax-3 has been used in the Tour going back through (but not prior to) the EPO era. Here's how Froome's performance rated:

Put in the mere context of time--how long it takes to climb a mountain--Froome's performance should raise eyebrows for several reasons: (1) he was faster than confessed dopers; (2) he was much faster than his closest competition.

The second part of this is especially important, since it suggest that the speed wasn't influenced by external factors: wind, change in pavement smoothness, bike equipment, and so forth. It means that it was Froome, not the conditions, that was extraordinary.Extraordinary W/kg
If it were left at this, there would be little controversy. After all, we have the numbers in front of us--the clock doesn't lie, but then, it also doesn't tell the full story, as those of us on Strava know.

But Vayer and company go on.

They have bought into two premises:
(1) Using nothing more than a stopwatch, gradient, and rough wind speed, anyone can estimate the performance (w/kg) of anyone;
(2) Performance above a certain level is evidence of performance enhancing drug use.

The idea that we can know dopers by their estimated W/kg has been around for years. Science of Sport advanced the idea with their wonderful analysis of Contador's 2009 attack on Verbier. They estimated Contador's relative power output to be 6.78 W/kg.

Recently those who use estimated W/kg have become more bold, using it less as a comparative tool, more as evidence. These have have found an eager audience following Armstrong's confession.

There has also been a backlash from a number of top sports scientists. Their response, too often, has been that of Hunter Allen: Trust me. I'm an expert. It's the same response we used to get from Chris Carmichael. It's deeply patronizing, since it doesn't address the question; it merely says, "trust me [because I'm smarter than you]."
Allen's partner in writing, Andy Coggan, pointed to a more reasoned response on Aeroweenie's blog. We can't estimate Watts/kg, the author asserts, because the range of possible estimation is too large. Just a few pounds difference in rider weight, wind speed, or the effect of drafting can skew results. Stick with speed as a necessarily vague estimator of output, he suggests.

This all could be avoided if Froome had continued to publicize his power data, as he once did. Before he joined Sky, Froome provided his power data to Bike Pure. He stopped sending the group his data 18 months ago, and with no explanation.

Froome may have good reasons for keeping his training data secret, but a number of riders now freely publish their rides or upload Strava segments, Sky teammate Joe Dombrowski and Laurens ten Dam being among the most open with this kind of information. Ten Dam's openness with his data hasn't prevented him from riding into the top ten in this year's Tour.

Nor has it stopped ten Dam from driving a sweet Chevy van:

Extraordinary VAM
Well, if we can't get Froome's power and weight, are we stuck with mere speed? No. We can also take into account his vertical movement--find out how fast Froome went up the mountain. Simple. Right?

The metric for measuring speed
up a mountain is VAM--vertical ascent meters/hour. The formula for calculating VAM is:

Meters ascended * 60 / minutes

Ax-3 Domaines' climb is 670 meters, and the ascent took Froome 22:14.

Plugging in the data:

670*60/22.23 = 1,808 VAM

How does Frome's 1,808 compare with the climbers of the past--particularly the doped climbers? Well, quite well. Here's a graphic showing the highest recorded VAMs of major
climbs of the Tour:

(Courtesy Science of Sport)

Using VAM as a metric puts Froome's performance on or above the level of the all-time champs of doping.Extraordinary? Yes. Certainly drug-enhanced? No.
Froome's defenders can point to two variables thus far overlooked (aside from the flaws in the W/kg estimation model): duration and steepness.

Those of us with Hunter and Coggan's excellent book are aware of the notion of the power profile. The power profile illustrates what we all already know--that our average W/kg for a sprint is different than our average W/kg for a longer effort.

Many of us have plotted out our profiles. They look something like this:

The shape of the curve indicates the type of rider. This graph, for instance, has mapped two power curves. The yellow line indicates a profile capable of averaging 250w for 20 minute efforts and somewhere near 240 for 45 minutes.

Ax-3 Domaines is a short climb, about the same length as Verbier (640m), but Froome's VAM is much less than Contador's 2009 effort on Verbier.

Those who argue for Froome could point to the relative shortness of his effort on Ax-3 Domaines. Of course Froome was fast up a 22-minute climb! It's half the length of Ventuox!

Note, if Froome maintains a 1808 VAM on Ventoux on stage 15 when the Tour moves to the Alps, this argument will no longer apply.

Further to Froome's benefit is slope. As even Michele Ferrari in his own analysis suggests, steeper climbs yield higher VAMs. Ax-3 Domaines is significantly steeper (at 8%) than Verbier (7.1%). This means his performance is less extraordinary, relative to Contador's 2009 ascent of Verbier.

While not clearing Froome of suspicion, the steepness of Ax-3, along with its shortness, suggests that his performance, while extraordinary, still falls short of the juiced era's best.

Conclusion
We have to travel backwards three decades to unearth a performance we
can feel certain was unaided by EPO. Such have been the revelations of
the past year. Skepticism toward the extraordinary in this context? Well, it's due.

But we should also hold out hope. One thing David Millar's wonderful memoir, Racing Through the Dark, argues is that clean cyclists can compete with and sometimes triumph, even against dopers. This suggests that the benefits of doping are perhaps not as massive as we once thought, and that sometimes, possibly, racing against dopers perhaps pushes clean riders to train and improve.

Wittgenstein once said about the limitations of language, "whereof one cannot speak, thereof one must be silent." Even if Froome provided his power data (as he once did) and gave us a sort of language with which to compare his performance with the performance of dopers past, it would not answer the question of whether he doped.

It's mere speculation to infer cause from effect, but that doesn't mean we should, as Hunter Allen urges us, to "shut yo mouths." If there's one thing to keep dopers on edge, it's the kind of scrutiny Froome has been forced to undergo. While it may be uncomfortable for him, if he is doping it must surely be downright torture.

14 comments:

First off, thanks for this article. Well done. Secondly, you have misquoted me in both instances and also given the reader a false sense of tone. I am not exactly sure how you can be sure of tone from a rant I posted on FB and Wattage list, but unfortunately you didn't get it right. (who is this anyway, your name is not anywhere on this article. I guess you are anonymous?)

While it might have appeared that my post was to say the article and authors in question were not as intelligent as they think they are, that was not my intention and your post implied that and attempted to put words in my mouth. I am sure these guys are very sharp. However, their problem is a lack of data. They have written entire articles, promoted them and pushed out to multiple media sources and the purpose of these articles are out to prove that anyone over 6.1xx w/kg is a doper. They are operating on 'lack of data'. If they did have access to the best in the world at one time or another, then they would know the real truth. For years, I have seen data from winners of grand tours and others that I would consider clean riders (never tested positive, did not come from the era of structured doping programs, know some of them personally, ride on teams that have strict anti-doping policies, etc). These elite of elite riders ride over 6.2 w/kg on a regular basis. And the superstars are over 6.3, with a peak of form now at 6.5. So, while Vayer, etc. have an interesting article, it’s based upon 'lack of data' not lack of intelligence.

Your second misquote is an outright insult. "Shut yo mouths" is something I would never say in person, or on a forum. Please remove this as its offensive and an outright lie. I never urged anyone to "shut yo mouths". What you are probably referencing is my assertion that Froome is clean and yes, he's doing 6.5w/kg legally and he's gotten there through superior training with a power meter and superior coaching and support so get over it. Team Sky is and should be a wakeup call to all the rest of the professional cycling teams. They are the most professional of all the professional teams, with the possible exception of Vaughters' Garmin/Sharp team.

The problem with this information is that for one reason or another, it's confidential. Kinda like how your bank account is confidential, I could write an article to try and prove you have $859,013.98(speaking hypothetically here of course) in the bank account based on your spending patterns, size of your house, type of job you have, clothes you wear, cars you drive, vacations you take, etc. But, only you would know that you have $2,845,313.00 in the bank. My article would be wrong, but would you really want to come out to the world and tell them the exact amount in your bank account?

The data is there, but isn't allowed to be shared. This is a problem and I hope that in the future teams will allow their riders to release their data, because after having been in this game for over 13 years now, I just don't see a disadvantage for the athlete in competition. The rider can know his competitors FTP and even ride alongside him up a climb and look over at his PM to see how many watts he's doing. But, he still has to pedal the bike.

The bottom line of your article is spot on and well written. We should hold out hope. I know riders on one team that are so scared of testing false positive that they won't even take a simple multi-vitamin. The administration of that team has drilled it into their heads so many times the negative consequences of any positive test, that the riders are riding scared. These riders will be fired, required to return all salaries/money earned while on the team and will also be sued by the team for damages. Not something that an aspiring 20 year old on a big pro team would ever want to face. My point being is that I personally believe that the peloton is cleaner than ever and I know that 6.5 w/kg is possible by clean riders.

Hunter, I'm a big fan of your work, and I believe you've worked with Jeremiah Bishop and Joe Dombrowski--two guys I believe are clean, and who are world class.

Your athletes and your writing are known for use of data. It's this reliance on metrics and tools of analysis that makes yours and Andy's work so powerful. You removed much of the mystery of coaching; we are not acolytes. Chris Carmichael, you are not.

Now, you're asking us to give up on this very pursuit and to take your word for it. Now, I respect your authority on this. It carries weight. But I want to see the data! The power files! You are in the Holy of Holies, man!

Clearly, Paps' diatribe was not only about you ask (trust me!), but what, uncharitably, I'll call jealousy. More charitably, i'll call it the pursuit of knowledge.

We all want to be fast. Froome fast. We want the data that made him fast. After all, you convinced us it was data, not magic, that can make us fly.

Froome is mere seconds behind the world champion time trialist Tony Martin and also beating the best climbers up the mountains? Child, please. He is doping to the gills. Just remains to be seen on what.

Virenque today, translated: "Totally acceptable and believable perfomance, middle of the pack rider in Continental races for years, average clocker (time trialist), and can easily respond to attacks made by a world-class Colombian that weighs 12kg less than him in a Grand Tour on a 10% ramp, like Sir Dave, (mockingly) I also don't believe in physics, logic, or sharing performance data, I just believe in heart. All you need is heart. All the greats have heart, guys like me, Pantani, Vino, Di Luca, Armstrong, it's just heart. Unfortunately it's a heart of darkness."

I agree with the Annon - who said you paraphrasing of course, that you want us to believe that Froome can be up there with Tony Martin a top class time trialist, OK that would be possible of course, oh but that's not all he can beat and not just beat totally outclass Contador et al on the climbs. I don't believe in Froome at all, he's a doper.

While it might have appeared that my post was to say the article and authors in question were not as intelligent as they think they are, that was not my intention and your post implied that and attempted to put words in my mouth